The diagnostic value of anti-cyclic citrullinated peptide (CCP) antibodies in children with Juvenile Idiopathic Arthritis

Background. Antibodies against cyclic citrullinated peptide (anti-CCP) are considered to be specific for rheumatoid arthritis (RA). Objective. To assess the clinical significance of anti-CCP antibodies in a cohort of patients with juvenile idiopathic arthritis (JIA) and if they can be used to identify patients with an unfavourable course of disease. Methods. 68 serum samples were investigated. 45 patients were diagnosed with JIA (15 male and 30 female) aged 1.9-17.3 years (median 12.9 mean 11,0). 5 patients had polyarticular (RF negative), 2 polyarticular (RF positive), 25 oligoarticular JIA, 6 enthesitis related arthritis, 2 psoriatric arthritis, 3 patients had systemic disease and 2 unclassified arthritis. 23 samples were taken front patients with non-inflammatory cardiac diseases undergoing interventional cardiac therapy. Enzyme-linked immuno-sorbent assay (ELISA; Euroimmun, Lubeck, Germany) was used for the detection and quantification of antiCCP antibodies in patients with JIA. Results. Overall, anti-CCP antibodies were found in 2.9% (2168) of all samples and in 4.4% (2145) patients with JIA. Conclusion Anti-CCP antibodies are associated with RF positive polyarticular course of JIA. Anti-CCP antibodies are not relevant for other subgroups of JIA. Therefore anti-CCP Abs in patients with JIA should not be investigated routinely.